With water-conducting household appliances such as dishwashers for example, to prevent the line system in which washing liquor is circulated becoming contaminated by contamination particles, a filter system is used which can comprise a coarse-mesh filter, a fine-mesh filter and a micromesh filter. In such cases the coarse-mesh filter serves to hold back contamination particles which can lead to a blockage of the drain pump. Particles with a particle size of larger than approximately 1 mm are held back by a fine-mesh filter and particles with a particle size larger than approximately 0.15 mm are held back with a micromesh filter.
A water-conducting household appliance such as a dishwasher for example has a drain pump with which contaminated washing liquor can be conveyed out of the dishwasher into a domestic waste water drainage system at the end of the washing cycle. Such drain pumps are designed to enable them to convey larger particle sizes without hindrance and without the drain pump becoming blocked. Thus drain pumps are arranged such that the contaminated washing liquor is only coarsely filtered when pumped away.
In addition a dishwasher features a recirculation pump with which washing liquor can be circulated during the cleaning process, i.e. liquid collecting in the pump sump of a dishwasher is fed by means of the recirculation pump through a hydraulic system to spray arms arranged within the tub with which an even application of washing liquor to the items to be washed is undertaken. The spray arms have comparatively small openings so that it is necessary to guide the circulated washing liquor through the fine-mesh and micromesh filters so that the smallest particles are held back and the outlet openings of the spray arms cannot become blocked. Accordingly the recirculation pump is embodied in relation to the particle size tolerance.
The spray arms of a dishwasher can be supplied alternately with washing liquor during a washing process at predetermined intervals set by the washing program. In this way, despite a reduced amount of washing liquor overall, the washing liquor can be applied with high kinetic energy to the items to be washed.
A generic dishwasher is known from DE 24 28 991 A1, the spray apparatus of which can operate in this type of alternating mode. To this end the dishwasher features a switch-over element which, on actuation enables the washing liquor to be guided to a first liquid line leading to the first spray apparatus and/or to a second liquid line leading to the second spray apparatus.